As I wrote elsewhere in this thread [1], the data in the article shows desktop computing down significantly in Q3 2020. That came as a surprise to me. I would have expected it to be up since so many are stuck at home and desktop computing remains the premium home computing experience. If you've got a good work desk, desktop computing will push the value of each dollar spent on hardware further. Apparently most people still prefer to pick up a computer and move from room to room during their lockdown. That's not compelling for me, but it presumably is for others.
I have a 3900X desktop workstation and a 4900HS laptop, an Asus G14. You are right that the performance delta for most tasks is not as large as it was 15 years ago. In fact, for routine work, they seem about the same. The advantages to a desktop are things that I personally find valuable: ease of connecting many large displays (I use three 30 inch 16:10 monitors), ease of equipping large amounts of memory (32GB is a piece of cake, 64+GB is also easy on a desktop), tidier connectivity (everything is routed to a box hidden away behind the desk), no thermal throttling (always the same performance regardless of workload), quiet (larger and more powerful cooling), etc.